diff --git a/tox.ini b/tox.ini
index 1de0f2d..15c9cec 100644
--- a/tox.ini
+++ b/tox.ini
@@ -3,14 +3,13 @@
 [tox]
 envlist =
     check,
-    {py37,py36,py35},
+    {py3.7,py3.6},
     docs
 
 [testenv]
 basepython =
-    py37: {env:TOXPYTHON:python3.7}
-    py36: {env:TOXPYTHON:python3.6}
-    py35: {env:TOXPYTHON:python3.5}
+    py3.7: {env:TOXPYTHON:python3.7}
+    py3.6: {env:TOXPYTHON:python3.6}
     {bootstrap,check,docs}: {env:TOXPYTHON:python3}
 setenv =
     PYTHONPATH={toxinidir}/tests